One basic tablet a day with food if your diet is poor or you have increased needs.
Recent signal of less cognitive decline in older adults.
View the study (RCT) →Useful as a safety net if the diet is insufficient.
Does not clearly reduce heart attacks, cancer, or mortality in well-nourished people.
*⏱ 2 min read
Micronutrient deficiencies are more prevalent than most people believe: up to 70% of Americans do not get enough vitamin D, almost 50% do not meet their magnesium needs, and 35% have an insufficient calcium intake; these deficiencies have real consequences for health, since vitamin D insufficiency increases the risk of mortality, magnesium deficiency may accelerate biological aging, and folate deficiency can cause a level of DNA damage equivalent to that of an acute radiation exposure.
The case for a multivitamin as nutritional insurance is pragmatic and well founded: although diet should be the main source of most of our nutrients, it can be hard to achieve optimal nutrition from whole foods alone, and the cost of a multivitamin is low compared with the potential benefit of correcting minor individual deficiencies that are highly specific to each person; about a third of adults already take one for similar reasons.
The strongest evidence in favor of multivitamins comes from their effect on brain function: the COSMOS study, a 3-year randomized trial, showed that taking a daily multivitamin improved cognitive function, memory, and executive function compared with placebo; a meta-analysis of three COSMOS substudies concluded that multivitamin supplementation clearly improved global cognition and memory, with an estimated effect equivalent to a 2-year reduction in cognitive aging.
For major diseases and mortality, the data are less clear and convincing: multivitamins do not appear to reduce the risk of cardiovascular disease, cancer, or all-cause mortality overall, although the risk of lung cancer was 38% lower in participants who took multivitamins; a study published in JAMA in 2024 found a 4% increase in the risk of all-cause mortality in daily multivitamin users, although this association had hazard ratios very close to 1 and may reflect unidentified confounding factors.
The practical conclusion is that most people should take a multivitamin as a form of nutritional insurance to obtain micronutrients that may be harder to get from food; exercise, sleep, and diet are exponentially more important for longevity, with or without a multivitamin, and worrying about whether a multivitamin shortens life is worrying about the wrong things; you should not stop taking it based on the results of a single study, because there is an enormous difference between multivitamins not being linked to greater longevity and being linked to lower longevity.
Information, not medical advice. Scientific evidence reflects the quality of the studies.